The Mediating Effect of Waist Circumference and Fasting Plasma Glucose on the Association between Obstructive Sleep Apnea Syndrome and Arterial Stiffness in a Population Aged 40-65 Years

Abstract

Background Obstructive sleep apnea syndrome (OSAS) is a sleep-related disease. Evidence has shown that OSAS may increase the risk of developing arterial stiffness (AS) , but the mechanism of action still needs to be further explored. Objective To explore the mediating effect of waist circumference (WC) and fasting plasma glucose (FPG) on the association between OSAS and AS. Methods A total of 1 053 health examinees were selected from Physical Examination Center, the First People's Hospital of Fuquan City from March 23 to November 30, 2022. General demographic data were collected. The risk of OSAS was assessed using the STOP-Bang Questionnaire (high or low risk of OSAS was diagnosed by STOP-Bang score ≥4 points or <4 points) . AS was assessed, and 553 cases with AS and 500 without were assigned to AS and non-AS groups, respectively. Multivariate Logistic regression analysis was used to explore the factors associated with AS. FPG was converted to exponential form (-2.576 1) to obtain the exponential value of FPG (FPGa) . Multiple linear model was used to analyze the relationship of OSAS with WC and FPGa. The mediation effect of WC and FPG between OSAS and AS was analyzed using Hayes Process models 4 and 6 in R. Results AS and non-AS groups had statistically significant differences in mean age, sex ratio, prevalence of smoking and hypertension, mean body mass index, WC, neck circumference, FPG, triglyceride, and high-density lipoprotein cholesterol as well as the level of OSAS risk (P<0.05) . Multivariate Logistic regression analysis showed that compared with individuals with low-risk OSAS, the risk of AS increased in those with high-risk OSAS (P<0.05) , and the risk of AS increased by 0.048 times for every 1 cm increase in WC and 0.512 times for every 1 mmol/L increase in FPG (P<0.05) . Multiple linear regression analysis showed that OSAS was associated with WC and FPGa (P<0.05) , and WC was an associated factor of FPGa (P<0.05) . The chained multimediator model showed that OSAS directly affected the incidence of AS〔β=0.661, 95%CI (0.284, 1.038) 〕. The indirect mediation effect value (β) of the "OSAS→WC→AS" path was 0.224〔95%CI (0.073, 0.398) 〕, accounting for 20.86% of the total effect. The indirect mediation effect value (β) of the "OSAS→FPGa→AS" path was 0.115〔95%CI (0.024, 0.216) 〕, accounting for 10.71% of the total. The indirect mediation effect value (β) of the "OSAS→WC→FPGa→AS" path was 0.074〔95%CI (0.036, 0.126) 〕, accounting for 6.89% of the total. Conclusion WC and FPG may partially mediate the relationship between OSAS and AS. In addition, they are involved in the process of "OSAS→WC→FPGa→AS" as chained mediators. People with high risk of OSAS should actively control WC to reduce the possibility of developing central obesity, and regulate FPG to prevent the occurrence of AS.

Keywords

• arteriosclerosis|sleep apnea, obstructive|fasting plasma glucose|waist circumference|mediation analysis|root cause analysis|correlation analysis